Refactor ALL the things!

src/parsers/many.c

@@ -0,0 +1,145 @@
+#include "parser_internal.h"
+
+// TODO: split this up.
+typedef struct {
+  const HParser *p, *sep;
+  size_t count;
+  bool min_p;
+} HRepeat;
+
+static HParseResult *parse_many(void* env, HParseState *state) {
+  HRepeat *env_ = (HRepeat*) env;
+  HCountedArray *seq = h_carray_new_sized(state->arena, (env_->count > 0 ? env_->count : 4));
+  size_t count = 0;
+  HInputStream bak;
+  while (env_->min_p || env_->count > count) {
+    bak = state->input_stream;
+    if (count > 0) {
+      HParseResult *sep = h_do_parse(env_->sep, state);
+      if (!sep)
+	goto err0;
+    }
+    HParseResult *elem = h_do_parse(env_->p, state);
+    if (!elem)
+      goto err0;
+    if (elem->ast)
+      h_carray_append(seq, (void*)elem->ast);
+    count++;
+  }
+  if (count < env_->count)
+    goto err;
+ succ:
+  ; // necessary for the label to be here...
+  HParsedToken *res = a_new(HParsedToken, 1);
+  res->token_type = TT_SEQUENCE;
+  res->seq = seq;
+  return make_result(state, res);
+ err0:
+  if (count >= env_->count) {
+    state->input_stream = bak;
+    goto succ;
+  }
+ err:
+  state->input_stream = bak;
+  return NULL;
+}
+
+static const HParserVtable many_vt = {
+  .parse = parse_many,
+};
+
+const HParser* h_many(const HParser* p) {
+  HParser *res = g_new(HParser, 1);
+  HRepeat *env = g_new(HRepeat, 1);
+  env->p = p;
+  env->sep = h_epsilon_p();
+  env->count = 0;
+  env->min_p = true;
+  res->vtable = &many_vt;
+  res->env = env;
+  return res;
+}
+
+const HParser* h_many1(const HParser* p) {
+  HParser *res = g_new(HParser, 1);
+  HRepeat *env = g_new(HRepeat, 1);
+  env->p = p;
+  env->sep = h_epsilon_p();
+  env->count = 1;
+  env->min_p = true;
+  res->vtable = &many_vt;
+  res->env = env;
+  return res;
+}
+
+const HParser* h_repeat_n(const HParser* p, const size_t n) {
+  HParser *res = g_new(HParser, 1);
+  HRepeat *env = g_new(HRepeat, 1);
+  env->p = p;
+  env->sep = h_epsilon_p();
+  env->count = n;
+  env->min_p = false;
+  res->vtable = &many_vt;
+  res->env = env;
+  return res;
+}
+
+const HParser* h_sepBy(const HParser* p, const HParser* sep) {
+  HParser *res = g_new(HParser, 1);
+  HRepeat *env = g_new(HRepeat, 1);
+  env->p = p;
+  env->sep = sep;
+  env->count = 0;
+  env->min_p = true;
+  res->vtable = &many_vt;
+  res->env = env;
+  return res;
+}
+
+const HParser* h_sepBy1(const HParser* p, const HParser* sep) {
+  HParser *res = g_new(HParser, 1);
+  HRepeat *env = g_new(HRepeat, 1);
+  env->p = p;
+  env->sep = sep;
+  env->count = 1;
+  env->min_p = true;
+  res->vtable = &many_vt;
+  res->env = env;
+  return res;
+}
+
+typedef struct {
+  const HParser *length;
+  const HParser *value;
+} HLenVal;
+
+static HParseResult* parse_length_value(void *env, HParseState *state) {
+  HLenVal *lv = (HLenVal*)env;
+  HParseResult *len = h_do_parse(lv->length, state);
+  if (!len)
+    return NULL;
+  if (len->ast->token_type != TT_UINT)
+    errx(1, "Length parser must return an unsigned integer");
+  // TODO: allocate this using public functions
+  HRepeat repeat = {
+    .p = lv->value,
+    .sep = h_epsilon_p(),
+    .count = len->ast->uint,
+    .min_p = false
+  };
+  return parse_many(&repeat, state);
+}
+
+static const HParserVtable length_value_vt = {
+  .parse = parse_length_value,
+};
+
+const HParser* h_length_value(const HParser* length, const HParser* value) {
+  HParser *res = g_new(HParser, 1);
+  res->vtable = &length_value_vt;
+  HLenVal *env = g_new(HLenVal, 1);
+  env->length = length;
+  env->value = value;
+  res->env = (void*)env;
+  return res;
+}